Method for process control in additive manufacturing

Abstract

A method is provided for controlling an additive manufacturing process in which one or more energy beams are used to selectively fuse a powder contained in an additive manufacturing machine having a gas flow therein in order to form a workpiece, in the presence of one or more plumes generated by interaction of the one or more energy beams with the powder, wherein the process is controlled by an electronic controller. The method includes: performing a build process to form a workpiece using a set of initial process parameters; sensing a condition of the finished workpiece; using the electronic controller, comparing the condition of the finished workpiece to a predetermined standard; using the electronic controller, changing one or more of the initial process parameters to define a set of revised process parameters; and performing a subsequent build process using the revised process parameters.

What is claimed is: 
     
       1. A method of controlling an additive manufacturing process, the method comprising:
 selectively fusing, with at least one energy beam, a powder contained in an additive manufacturing machine having a gas flow therein; 
 performing a build process to form a workpiece using a set of initial process parameters; 
 sensing one or more process conditions while building the workpiece, wherein the one or more process conditions includes a plume trajectory of at least one plume generated by interaction of the at least one energy beam and the powder; 
 sensing a condition of the finished workpiece; 
 controlling the build process with an electronic controller; 
 using the electronic controller, comparing the condition of the finished workpiece to a predetermined standard; 
 using the electronic controller to implement a software process to change one or more of the initial process parameters to define a set of revised process parameters configured to avoid interaction between the at least one energy beam and the at least one plume; and 
 performing a subsequent build process using the revised process parameters. 
 
     
     
       2. The method of  claim 1  wherein the sensed process conditions further include at least one of: thermal mapping, and gas flow. 
     
     
       3. The method of  claim 1  further comprising using the electronic controller for closed-loop control of one or more process parameters based on the sensed process conditions. 
     
     
       4. The method of  claim 1  further comprising taking a discrete action in response to the measured workpiece condition exceeding one or more predetermined workpiece condition limits. 
     
     
       5. The method of  claim 1  further comprising changing at least one process parameter of the additive manufacturing process in response to a change in performance of the additive manufacturing machine. 
     
     
       6. The method of  claim 5  wherein the change in performance is caused by wear or damage of the additive manufacturing machine. 
     
     
       7. A method of making a workpiece, comprising:
 depositing a powdered material in a build chamber disposed in a housing, while using a gas flow apparatus coupled in fluid communication with the housing to provide a gas flow over the powder; 
 in the presence of the gas flow, directing one or more energy beams to selectively fuse the powdered material in a pattern corresponding to a cross-sectional layer of the workpiece, wherein interaction of the one or more energy beams with the powdered material generates one or more plumes entrained in the gas flow, wherein the build process is conducted using a set of initial process parameters; 
 sensing a condition of the finished workpiece; 
 sensing one or more process conditions while building the workpiece, wherein the one or more process conditions includes a plume trajectory; 
 using an electronic controller, comparing the condition of the finished workpiece to a predetermined standard; 
 using the electronic controller to implement a machine learning algorithm to change one or more of the initial process parameters to define a set of revised process parameters configured to avoid interaction between the one or more energy beams and the one or more plumes; and 
 repeating the steps of fusing the powdered material to make a workpiece, using the revised process parameters. 
 
     
     
       8. The method of  claim 7  wherein the sensed process conditions further include at least one of: thermal mapping, and gas flow. 
     
     
       9. The method of  claim 7  further comprising using the electronic controller for closed-loop control of one or more process parameters based on the sensed process conditions. 
     
     
       10. The method of  claim 7  further comprising taking a discrete action in response to the measured workpiece condition exceeding one or more predetermined workpiece condition limits. 
     
     
       11. The method of  claim 7  further comprising changing at least one process parameter of the additive manufacturing process in response to a change in performance of the additive manufacturing machine. 
     
     
       12. The method of  claim 11  wherein the change in performance is caused by wear or damage of the additive manufacturing machine. 
     
     
       13. The method of  claim 1 , further comprising distinguishing, with the electronic controller, the at least one plume from the gas flow. 
     
     
       14. The method of  claim 7 , further comprising distinguishing, with the electronic controller, the one or more plumes from the gas flow.